For a control of performance features in a communication network, particularly a private communication network, a coupling of the communication system, particularly private branch exchanges, to an application means via an application interface or, respectively, ACL interface is provided. According to this application interface, the private communication system, for example, the communication system HICOM 300 of Siemens AG, is physically connected to the application means via a V.24 interface or, alternatively, via an ISDN basic interface (SO). The application interface is preferably realized in administration and maintenance unit (an integrated administration and maintenance server in the communication system HICOM 300) of a communication system and controls the communication exchange according to a defined protocol, for example, MSV1, with defined messages. The information embedded into the messages correspond to the switching-oriented instructions and event messages of the communication system. The program structure or, respectively, a switching routine that is suitable therein for execution of the switching-oriented instructions and for generating the switching-oriented event messages, i.e. a program structure or, respectively, a switching routine that supports a DVA-controlled call setup is provided as link element between the application means and the communication system, whereby the connection control is influenced by the switching-oriented instructions and the current switching-oriented status of connections is indicated by the switching-oriented event messages, i.e. those as well that are in the course of call setup.
Specific connections, for example, data communication can be undesired in communication systems and should not be switched. Further, call setups with, for example, invalid destination call numbers or, respectively, destination call numbers that are no longer allowed are to be supported such by the communication system that a call setup to the alternatively allowed communication terminal equipment is enabled.